BioTechPlex Corporation proposes to develop an improved aerosol delivery system. The proposed system, Concentrated Aerosol Delivery and Quantization System, CADAQS, will fulfill the need to acutely deliver high particle number concentrations of aerosols to the respiratory tract of small animals (rats, young rabbits, and guinea pigs: wt < 1000 g), while enabling the quantization of their deposition in the lungs. The CADAQS consists of 3 subsystems. A) A two stage aerosol concentrator, TSAC, concentrates aerosols of 1-5 pm AMMD. B) A Small Animal Aerosol Delivery System, SAADS, a zero-dead space nose cone incorporated into a whole body plethysmograph complete with sensors and data acquisition and analysis system. C) A Quantitative Aerosol Deposition System, QADS, utilizes a pair of 4 pixelated CdZnTi detectors with integrated ASIC placed laterally to each lung. In Phase I, we successfully constructed the TSAC prototype. In this Phase II project, we will construct the complete CADQAS system so that prototypes of commercial systems can be generated. The system will be tested using rats. The TSAC, the SAADS, and the QADS are designed to be sold as stand-alone devices as well as components of CADAQS. Such a system is not available commercially. This system will be used for environmental and occupational toxicology. It will also greatly facilitate the processes of drug discovery, toxicology and pharmacology through the delivery of drugs to the respiratory tract for both local and systemic drug delivery. PROPOSED COMMERCIAL APPLICATION: This system is designed to deliver concentrated aerosols to small animals while enabling the quantization of aerosols deposited in the lungs. This system can also act as a forerunner of the development of technologies for measuring cardiopulmonary function and aerosol delivery to premature infants.